During the first year, hardware and a computer algorithm for reliably measuring the blood pressure of an ambulatory patient using the cuff-Korotkoff sound method was developed and tested. A prototype micropressure transducer array that can noninvasively measure the arterial pressure waveform when placed over the radial artery was also developed. During the second year, a wearable system that can record the ECG and parameters necessary to determine automatically an ambulatory subject's blood pressure with the cuff-Korotkoff sound method will be developed. This system will use a high-fidelity lightweight digital cassette recorder that records for 12 hours on a single cassette; the recorder is being developed on another NIH project. All components of the continuous blood pressure measuring system will be developed. The transducer will be upgraded to a wearable system designed to minimize its size. Bench model versions of other components, such as signal conditioning, amplifiers, load controller, channel selection logic, and a calibrator will also be developed.